The present invention relates to search systems generally, wherein a query is processed to return search results, and more particularly to techniques for modifying queries before presentation to a sponsored search generator or other matching system where modifications improve coverage without a corresponding reduction in relevance.
With the advent of the Internet and the multitude of web pages and media content available to a user over the World Wide Web (web), there has become a need to provide users with streamlined approaches to filter and obtain desired information from the web. Search systems and processes have been developed to meet the needs of users to obtain desired information. Examples of such technologies can be accessed through Yahoo!'s website, Google's website and other sites.
Typically, a search process involves a user inputting a query to the search system and the search system returning one or more search results (“hits”) that are deemed responsive to the query. Many search providers also display sponsored links along with the search results, where the main search results result from searching a corpus such as a collection of Web pages referenced by an index and where the sponsored links are found in a database of sponsored links set up to supply relevant links to searchers on behalf of sponsors.
Ideally, the sponsored links that are provided are relevant to the query. For example, if a searcher (which can be a person, a person using a computer, or a computer) submits a search query in the form of a search query string such as “European vacation”, the search engine might find pages from the Web that are deemed to relate to vacationing in Europe. The sponsored search links might be found from the sponsored link database according to purchased keywords.
Thus, a travel agent sponsor might pay to have a link they devise presented to queriers that use “European vacation” in their search query. Often, sponsored advertising links are sold using a “pay per click” model, wherein the search system might present a sponsored link, but the sponsor only pays the search system operator when and if the querier clicks on the sponsored link.
With a pay per click model, the search system operator would like to ensure that the sponsored links are relevant to the search. If, for example, sponsored links for auto repair are displayed with search results for vacations, it is not likely that the reader will be interested, and such links would have a very low click-through rate and the search system operator would not see much revenue. On the other end, if the search system is too strict about what it shows, insufficient coverage might result.
A sponsor typically identifies in advance one or more search query strings that should trigger the display of the sponsor's presentation. Each sponsor's presentation might be indexed against one or more of these pre-selected search query strings. Each time a search query is entered, the search system attempts to match the search query with as many of the search query strings that have been pre-selected by the sponsors as possible. When a search query submitted by a user is relevant to one of the pre-selected search query strings, a sponsor presentation could be displayed along with the other search results.
As sponsors typically indicate the keywords that are needed in a search query and expect that their sponsored presentation would not be shown at random, there are some search queries that would have no matching presentations. For example, the search query “John Q. Public's Daily Breakfast Menu” might not attract any interested sponsors, so users submitting that as a search would not see any sponsored links. Ideally, the “coverage” of search queries would be such that a large proportion of the searches performed would be covered by at least one relevant sponsored presentation. Otherwise, where search queries are not covered by any sponsored presentations, the search system operator would not see any sponsored presentation revenue for those search queries. Thus, there is a tension between casting too wide a net and having possibly irrelevant sponsored links, which would over time cause users to ignore them, and casting so narrowly that insufficient coverage results.
It would therefore be desirable to provide techniques for increasing the coverage of sponsored presentations that are returned in response to search queries while maintaining relevance or lowering instances where sponsored presentations might be deemed to be less relevant.